Promoting effect of rapamycin on osteogenic differentiation of maxillary sinus membrane stem cells.

BACKGROUND: Stem cells located in the maxillary sinus membrane can differentiate into osteocytes. Our study aimed to evaluate the effect of rapamycin (RAPA) on the osteogenic differentiation of maxillary sinus membrane stem cells (MSMSCs). METHODS: Colony-forming unit assay, immunophenotype identification assay, and multi-differentiation assay confirmed characteristics of MSMSCs obtained from SD rats. Transmission electron microscopy (TEM) and flow cytometry (FCM) identified the initial autophagic level of MSMSCs induced by RAPA. Real-time quantitative PCR (qPCR) evaluated subsequent autophagic levels and osteogenic differentiation. Alkaline phosphatase (ALP) activity assay and alizarin red staining (ARS) evaluated subsequent osteogenic differentiation. We performed a histological examination to clarify in vivo osteogenesis with ectopic bone mass from BALB/c nude mice. RESULTS: MSMSCs possessed an active proliferation and multi-differentiation capacity, showing a phenotype of mesenchymal stem cells. The autophagic level increased with increasing RAPA (0, 10, 100, 1,000 nM) and decreased over time. ALP activity and calcium nodules forming in four RAPA-treated groups on three-time points (7, 14, 21 d) showed significant differences. Col1a1, Runx2, and Spp1 expressed most in 100 nM RAPA group on 7 and 14 d. Osteogenesis-related genes except for Ibsp expression between four groups tended to be consistent on 21 d. 100 nM and 10 nM RAPA-treated groups showed more bone formation in vivo. CONCLUSION: RAPA can promote osteogenic differentiation of MSMSCs, indicating a possible relationship between osteogenic differentiation and autophagy.

The role of the membrane of the maxillary sinus in space osteogenesis under the sinus floor after elevation of the sinus floor / 口腔疾病防治

@#With the continuous development of maxillary sinus floor elevation technology, the osteogenesis mechanism of maxillary sinus floor elevation has always been a concern of scholars. The membrane of the maxillary sinus is an indispensable physiological structure in the process of space osteogenesis under the sinus floor after elevation of the sinus floor. In recent years, the role of the maxillary sinus floor mucosa in sinus floor space osteogenesis has been a research hotspot. Recent studies have found that the maxillary sinus floor membrane plays a role as a natural biological barrier membrane in the process of sinus floor space osteogenesis after maxillary sinus floor elevation; in addition, it has the ability to undergo osteogenesis. It has also been found that maxillary sinus membrane stem cells (MSMSCs) derived from the maxillary sinus floor membrane have characteristics of mesenchymal stem cells, which can differentiate into osteoblasts and participate in sinus floor space osteogenesis after maxillary sinus floor elevation. New studies have also found that small RNAs such as microRNAs, long noncoding RNAs and circular RNAs can regulate the osteogenic differentiation of MSMSCs, which may be important biological targets for promoting osteogenesis in the sinus floor space. In this paper, the relationship between the maxillary sinus floor mucosa and bone formation after maxillary sinus floor elevation, the barrier and osteogenic function of the maxillary sinus floor mucosa, the sources of osteoblasts involved in osteogenesis of the sinus floor space, and the molecular regulatory mechanisms of stem cells derived from maxillary sinus mucosa will be elucidated step by step.

The regulatory mechanisms of IGF1 in the osteogenic differentiation of canine MSMSCs via BMP2⁃Smad 1/5 signaling pathway / 口腔疾病防治

Objective@#To investigate the role of the bone morphogenetic protein 2 (BMP2)⁃Smad1/5 and p38MAPK signaling pathways in the osteogenic differentiation of MSMSCs by insulin⁃like growth factor 1 (IGF1).@* Methods @#A re⁃ combinant adenovirus (RAD) and IGF1 expressing IGF1 gene were constructed. After osteogenic induction, qRT⁃PCR and Western blot were used to detect the phosphorylation level of Smad1/5 and the expression of the BMP⁃2 protein in the BMP⁃Smad signaling pathway; immunohistochemistry was used to observe the nuclear translocation of Smad1/5; qRT⁃PCR and Western blot were used to detect IGF with Noggin and SB203580, inhibitors of the p38MAPK signaling path⁃ way 1⁃mediated osteogenic differentiation of MSMSCs@* Results@#The recombinant IGF1 adenovirus was constructed suc⁃ cessfully. MSMSCs were cultured in inductive medium after infection with different concentrations of Ad⁃IGF1, and then, the protein levels of BMP2 and p⁃Smad1/5 increased. IGF1 can also induce nuclear translocation of Smad1/5. In addition, Noggin significantly reduced the phosphorylation level of Smad1/5 and the formation of mineralized nodules in the MSMSCs. The mRNA levels of Runx2, OPN and ALP also decreased. In contrast, SB203580 decreased neither the phosphorylation level of p38 nor the mRNA expression of Runx2, OPN and ALP in the Ad⁃IGF1 MSMSCs@* Conclu⁃sion@#IGF1 can promote the osteogenic differentiation of MSMSCs via the BMP2⁃Smad1/5 signaling pathway. In con⁃ trast, IGF1 may not promote the osteogenic differentiation of MSMSCs via the p38MAPK signaling pathway.

Hsa_circRNA_33287 promotes the osteogenic differentiation of maxillary sinus membrane stem cells via miR-214-3p/Runx3.

BACKGROUND: Circular RNAs (circRNAs) comprise a novel class of noncoding RNAs that play important roles in a variety of diseases. However, the mechanism by which circRNAs regulate the osteogenic differentiation of maxillary sinus membrane stem cells (MSMSCs) remains largely unclear. METHODS: Microarray analysis was used to explore the expression profiles of circRNAs during the osteogenic differentiation of normal and BMP2 induced-MSMSCs. CircRNA_33287 was identified by agarose electrophoresis, quantitative real-time PCR (qRT-PCR), and western blotting. The function of circRNA_33287 was assessed by loss- and gain-of-function techniques and Alizarin red staining. Potential miRNA binding sites for circRNA_33287, and the target genes of miR-214-3p, were predicted by using online bioinformatics analysis tools. The relationships among the regulatory roles played by circRNA_33287, miR-214-3p, and Runt-related transcription factor 3 (Runx3), during the osteogenic differentiation of MSMSCs were verified by use of the dual luciferase reporter assay, qRT-PCR, and western blotting techniques, respectively. In addition, the molecular sponge potential of circRNA_33287 for miRNA was assessed via in vivo ectopic bone formation and a histological analysis performed after hematoxylin and eosin staining. RESULTS: Expression of circRNA_33287 was confirmed to be up-regulated during the osteogenic differentiation of MSMSCS. Overexpression and silencing of circRNA_33287 increased and decreased the expression levels of key markers of osteogenesis, respectively, including Runx2, OSX, and ALP. Furthermore, circRNA_33287 acted as a molecular sponge for miR-214-3p, which regulated Runx3 expression by targeting its 3'UTR. Moreover, circRNA_33287 protected Runx3 from miR-214-3p-mediated suppression. In addition, circRNA_33287 was shown to increase ectopic bone formation in vivo and displayed the strongest ability to stimulate bone formation when co-transfected with a miR-214-3p inhibitor. CONCLUSION: The novel pathway circRNA_33287/miR-214-3p/Runx3 was found to play a role in regulating the osteoblastic differentiation of MSMSCs in the posterior maxilla.

Lnc-NTF3-5 promotes osteogenic differentiation of maxillary sinus membrane stem cells via sponging miR-93-3p.

BACKGROUND: The function and the mechanism of long non-coding RNAs (lncRNAs) on the osteogenic differentiation of maxillary sinus membrane stem cells (MSMSCs) remain largely unknown. MATERIALS AND METHODS: The expression of lnc-NTF3-5 and Runt-related transcription factor 2 (RUNX2), Osterix (OSX), and Alkaline Phosphatase (ALP) was examined by quantitative real-time PCR (qRT-PCR) in MSMSCs during the process osteogenic differentiation. Then the function of lnc-NTF3-5 was evaluated by loss- and gain-of-function techniques, as well as qRT-PCR, western blot, and Alizarin Red staining. In addition, the microRNAs (miRNAs) sponge potential of lnc-NTF3-5 was assessed through RNA immunoprecipitation, dual luciferase reporter assay, and in vivo ectopic bone formation. RESULTS: Lnc-NTF3-5, RUNX2, OSX, and ALP increased alone with the differentiation. Inhibition of lnc-NTF3-5 decreased the expression of RUNX2, OSX, and ALP both at mRNA and protein levels. Alizarin red staining showed similar trend. In contrast, overexpression of lnc-NTF3-5 presented totally opposite effects. Besides, overexpression of lnc-NTF3-5 could decrease the expression of microRNA-93-3p (miR-93-3p). Enhance miR-93-3p could also inhibit the expression level of lnc-NTF3-5. RNA immunoprecipitation demonstrated that lnc-NTF3-5 is directly bound to miR-93-3p and dual luciferase reporter assay proved that miR-93-3p targets 3' UTR of RUNX2 to regulate its expression. Ultimately, in vivo bone formation study showed that lnc-NTF3-5 and miR-93-3p inhibitor co-transfection group displayed the strongest bone formation. CONCLUSIONS: The novel pathway lnc-NTF3-5/miR-93-3p/RUNX2 could regulate osteogenic differentiation of MSMSCs and might serve as a therapeutic target for bone regeneration in the posterior maxilla.

Role of miR-27a in the osteogenic differentiation of beagle maxillary sinus membrane stem cells / 口腔疾病防治

Objective@#To detect the expression level of miR-27a during the osteogenic differentiation of beagle maxillary sinus membrane stem cells (MSMSCs) and explore the role of miR-27a in the osteogenic differentiation of MSMSCs.@*Methods@#Beagle MSMSCs were cultured in vitro. The expression level of miR-27a was detected via RT-PCR after an osteogenic inductive culture was prepared. The mRNA expression levels of Runx2 and OPN were examined via RT-PCR, and the protein expression levels of Runx2 and OPN were examined via Western blot after the cells were transfected with pre-miR-27a or anti-miR-27a. Finally, osteoprogenitor cells transfected with pre-miR-27a were composited with Bio-Oss particles and subcutaneously implanted into nude mice to form ectopic bone formation models, and then the inhibition of bone formation from miR-27a was observed in vivo. @*Results@#The expression level of miR-27a in the beagle MSMSCs decreased after osteogenic inductive culturing. The relative miR-27a levels were significantly decreased at day 1 (t=3.795, P=0.023), day 3 (t=4.493, P=0.011), day 7 (t=11.591, P < 0.001), day 14 (t=12.542, P < 0.001), and day 21 (t=5.621, P=0.008) compared with day 0. In addition, the expression levels of Runx2 mRNA (t=4.923, P=0.007) and protein (t=4.425, P=0.008) were reduced after the cells were transfected with pre-miR-27a. The expression levels OPN mRNA (t=5.253, P=0.006) and protein (t=5.132, P=0.006) were also reduced. In contrast, the mRNA expression levels of Runx2 (t=3.925, P=0.013) and OPN (t=3.712, P=0.019) were increased after the cells were transfected with anti-miR-27a, and bone formation was observed after the subcutaneous implantation of beagle MSMSCs composited with Bio-Oss in nude mice. Nevertheless, ectopic bone formation was inhibited by pre-miR-27a-transfected beagle MSMSCs composited with Bio-Oss (t=7.219, P=0.0020). @* Conclusion @# MiR-27a negatively regulates the osteogenic differentiation of MSMSCs.